Matter is conserved

Energy flows, but matter is recycled






















Each cycle includes aspects of Biology + Chemistry + Geology as elements move or are stored in the componenets of the biosphere

Importance of biogeochemical cycling: Nutrient limitation

Cycling = Transfer, transformation and storage

Biogeochemical cycles: Global

Nutrient cycles: Ecosystem


  • Entry of nutrients into system (IN)
    • fixation (bacteria)
    • weathering (rocks)
    • deposition (acid rain)


  • Internal transfer (recycling)
    • food webs
    • decomposition
    • inorganic - organic


  • Loss of nutrients from system (OUT)


  • Steady State and Succession….

Carbon cycle: Ecosystems

Carbon cycle: Global (Sinks and Sources of C)

Nitrogen cycle: Ecosystems

Nitrogen cycle: Ecosystems

Decomposition - ecosystem internal recycling

Decomposition rate: Biomes (climate+microbes+material)


Nutrient transfer: Soil commmunity

Nitrogen cycle: Global

Primary productivity: Generation of biomass

–>